And tonight, a mad scramble is under way across the country and online as the midnight hour approaches. It is the deadline to sign up for okbamacare at healthcare.gov. ABC's chief white house correspondent Jon Karl now on the sprint to the finish. Reporter: In Dallas today, hundreds of people waited in line to sign up for health care. Long lines in Miami, too, and San Antonio. Got here at 6:30, got in at about 9:20 and still here. Reporter: It looked like election day. The vp visited an enrollment center in Washington and made a last-minute pitch with Rachael ray. Any young person listening, if you don't need this for your peace of mind, do it for mom. Do it for your dad. Get health coverage, do it for mom. Reporter: Deadline day has brought an obamacare surge. By noon today, more than a million visitors. Even now, still glitches. The website down for hours. Even the countdown clock on the white house website was off. It wasn't 16 days until the deadline, but 16 hours. The white house dogs joined a white house push today that also saw some odd presidential appearances designed to appeal to young people. Have you heard of healthcare.gov. What did you come here to plug? Reporter: In a mashup of celebrity endorsements, parodied by "Saturday night live." The pitches may have worked, but many questions are still unanswered, including how many people have actually paid to enroll. How many of those who have signed up have actually paid? We don't have those figures. When we do, we'll get them to you. Reporter: The white house says 6 million have signed up, but they haven't been able to say how many of them were previously uninsured and mow many are young and healthy. Both critical measures of this law's success. All right, Jonathan Karl, thank you. And next, we turn to an urgent new warning from some of

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